Organic materials such as polymers, resins, lubricating oils and the like are often subject to thermal, oxidative and actinic induced degration. Various stabilizers including the organic phosphites have been developed to stabilize such materials.
Cyclic phosphites have achieved a firm place among the organic phosphite stabilizers. Typical of such organic phosphites are those taught in U.S. Pat. No. 4,318,845. In order to prepare such organic phosphite stabilizers, a key intermediate is first prepared by reacting an appropriate bisphenol with phosphorus trichloride to prepare the corresponding phosphorochloridite in the presence of an acid acceptor such as triethylamine.